Loud speaker



Dec. 8.,'1925. 1.564.763

V. DURBIN LOUD SPEAKER Filed oct. 2o. 19.24v

Patented ec, 8.. 1925.

y UNITED srfrssv imite" OFFICE.. 1

PATENT ELECTRIC COMPANY, F ROXBUR'Y, MASSACHUSETTS,

GEUSETTS.'

LOUD SPEAKER..

A oonronn'rron or Messn- App'icatlon led October 2f), 1924. Sex-tal No.744,542.

To all whom' t may concern:

Be it known that I, VERNON DURBIN, a citizen lof the United States,residing at Newton, in the county ofv Middlesex and 5 State ofMassachusetts, have invented certeinnew and useul Improvements in LoudSpeakers; and l do hereby declare the following to b e a full, clear,and exact descri tion of the invention, such as will enabe othersskilled in the art to which it appertains to make and use the same. Y'lhe present invention relates to an improvement in loud speakers.

The vobject of the invention is to reorgenis/.e and improve theconstruction of loud speakers, and to this end the invention consists inthe improvement hereinafter def scribed and particularly defined in the.

claims.

In the accompanying drawing illustrating the preferred form form of theinvention Fig. 1 is a sectional elevation of the base ot' theinstrument, and Fig. 2 is a bottom plan of the same.

The illustrated' embodiment of the rinvention is described as follows:The base 10 consists of a casting or bell of inverted dish form. lt isen heavy casting provided at its lower edge with a thickened lip 1]having u lgroove in its bottom to receive u leather cushion ring 12 uponwhich the base rests when it is standing on a support. Projectingupwardly from the bell is a horn holder 13 which receives the usual loudspeaker horn. A throat 14 smaller than the inside of the horn holderconnects with the sound' chamber 15. "The diaphragm 16 is support edcentrally below the throat, a rubber ring or diaphragm washer 17 beinginterposed 4U between the marginal portionof the dia.-

hragm vvand the under surface of the bell.

he diaphragm is secured in place by the clamping ring 18 which is aheavy brass ringv pressed against the under-side of the periph eralportion of the diaphragm.-k .The clamp ing ring is secured in place bymeans ot clamping' clips 19. These clips engage at their outer endsshelves 20 formed integrally with the bell, and at their inner ends withthe clamping ring. The shelves 20 are provided with lips 21 forconveniencing assembly. The clips are secured in place by screws 22which pass freely through holes in the clips and are screwed into screwholes 23 in the. bosses 24 projecting downwardly from the under side ofthe bell ut uniform intervals around the bell. The receiver comprisesthe magnet contained in the magnet-box 26. The magnet-box screwthreadedon its outer side und adapted to be screwed into the clamping ring 18which is correspondingly threaded to receive it. The magnet is providedwith two terminals 27 and 28 to which are attached the lendingin wiresQ5) and 30': The 'magnet-box is providedwith an adjusting erm 31 securedto the box und projecting downwardly and outwardly therefrom, as shown,'and having its end turned upwardly outside the lower edge of thebellwhere itmay be grasped by the hand and movedin one direction or theother. By moving the lever to the right the magnet-box is screwedfarther into the clamping ring, and themagnet is thereby caused tol bemoved closer to the diaphragm; by movement in the opposite direction itis adjusted to a greater 'distance therefrom. In the position shown inFig. 2 the magnetbox occupies the position of extreme adjustment ofthemagnet'toward the diaphragm. In order to prevent it from'being adjustedcloser than a certain predetermined distance from the diaphragm,I andincidentally to preventthe magnet from being brought into contact withthe diaphragm, thc magnetbox2 in assembling the parts, is screwed inuntil it occupies the position of closest de-` sirable approach to thediaphragm. and then the leather ring 12 is inserted in the groove in theunder side of the lip ofthe bell with its end '32 a einst the side ofthe arm 31, as shown in ig. 2. The l'ather ring is made ofsuch a lengththat its end 33 affords a stop for movement of the arm `in the oppositedirection, so that the magnet cannot loe` ad justed to a distance away'from the die phragm greater than thatfindicated when the arm 31 comesinto engagement with the end 33 of the leather ring 12.'

In assembling this instrument the bell is turned upsiden'down, therubber iring or` diaphragm washer `17 is inserted and positioned by; thebosses 24, the diaphragm 15 'i 1s llaid ontop of it1 the clamping ringis nextinserted and centered with respect to the diaphragm; then theclips, which have Previous1 ocou ied positions which Awould notinte erevwith the-insertion of -the rubnhreyvan, hut avoids iagonregini 35 eion.

ber ring, -iiiephragin anti demping ring",eie

new' turned intey epproximeteiy the posiu vtion shown' in 2, andihe'eerews 2Q are tightened so es therebgy to Secure the ciamp- 6- ingring and diaphragm 1n pes1t1on-The magnetboxwie now ser Wed, nito'theeenip-- ing ring, and when' it has been screwed into the position withthe magnet in position o oiosest operebie relation to the diaphragm ithe. ieather ring 32 sins'erteci with theend" against the edge o iithearm 3l., The ieedingf-in wires are then brought through the hole 3e andsecured to the binding posts 27 and The tie string 35 iis-tied to' one..of the oiipe 19 in the ii'suei fashion; then the appare/tue is coinpieteand ready oi sale, i

.it wiii be observed that the sonni chamben 151s thin miei ietand doesnot permit eey reverberetmg sounds to be generated 1n 2o it'whentheapparatus is in ,operation. 'it

iviii be observed that the rubber ring not oniy eiortis e goed supportfor the die the necessityY of nishi U e under side of the beii, theelasticity 'ing of the rubber tei-ting core of um' inequaiities,

The ciips are Screwed down to hoid'the Sti' demping ring firmly inpiece, 'and the iat- 'is matie et eneh strength este give edeqiie entirigid 'Support te the edge of the The eriinstment of the ma@ het with,reietion to the diaphragm. is ensiiy seenrei without: disturbance of theinstrumentby siinpiyteking hold ofthe adjuster'ni end'nioving it to thefiesired 'posiit is aise seen'thzit the rrei'igement sueh "es to reventbringing'the magnet into accident-ei enga ement with the die phi'iigm,which Wenig not only he ,an zich juetmexliti-neepehie of 'use eut wouldinvoive ,io the iiabiiity of pemnenent injnryto the die- The Aiee'the-rring ,in the [lower phragm.

edge of Adie heii aioi-d-s e eushion support 'for the beii enti preventsscratching. the table or other support 'upon which the ine struinent maystemt it ie io be further observe-:i 'tiietthe beii may he notitie oeast iron and neeiis no machine Work to ,finish it., A The 'iips besheet iron stampings. The adjusting erm not oniy serves asthe 5% ineensfor acijusting the position oi the niagnet with relation to thediaphragm, but aiso by reeeenof its distortion to the positionindicated' in Fig. l it operetes to heid the magnet-boit in adgusteeiposition. strninent is eheep, easiiy'mzmufaetlired and esseinbieci, andit maintains its assembled.

positions Without; liability of accidentel mehitigliistrnent. It isprovide with aned-A juetnient for the magnet positionY having `provifnonfor preventing .excessive edjustnient either or from the diephre no.Lhnseieeoribed 'the invention, W et Tiev (iis:

iiiniteiiy adjust the magnet toward the The in'u Leeegree 1. A iouciVspeaker having, in combina tion,v e, beii provified with eiip at thebot-I tom, a receiver supported in the beii hav ing e `i'negnet anddiaphragm ,and `provided with an adjusting arm foredjnsting the positionof the magnet with reietion to the diaphragm, such arm extending outentier the edge of the bell, and stopsfor engaging the arm' to preventit from being moved excessively eitherin the direction to diaphragm orin the opposite c iireotion:. 2', A. loud speaker having, m combina'-tion, a b'eil provided with an upvverdiydil provided witha'dis'continuous cushion ring i 'e-Xtenfiing around the bottomof'thebei! and hving its 'ends ixed Withreiation .to the .etijusting erin toconstitute stops therefor.

3, A loud 'speeier comprising e heil heving e hp et its lower edgeprovided with a groove to receive e.- cushion ring, e receivercomprising a megnet-box containing e meg het, e clamping ring, themagnet-box end clamping ring being screwthreaded to afi tord adjustmentof the position of the'box with .relation tothe clamping ring, e die#phregm Washer and diaphragm', the Washer taking against the under sideof the heli,4

the (haphi'agxn egeinstthe Washer, and. the demping ring-against thediaphragm, and ineens for holding the clamping ring inA piece. Y

4. A ioui speaker comprising a, heil having e rhorn' holder projectingupwardly therefrom and provided with 'e .throat in ihe beii et thebottom ot vthe here hoitiei'j entering into the beii chamber; ereceiver, comprising e. magnet-box carrying el mag 11et, e clampingring, a diaphragm :md iw phragin Washer, and means for cleii'iping theclamping ring ege-inst the diaphragm and wesher to heid the receiver' inpiece, consisting of 'e pluraiity of oiips each oon-A sisting of e'emseeured in piece by a. lsorevv,` the inside of the bellbeing')providedl with e series of shelves-corresponding in nuni ber tothe clips, and a plurality of bosses tof receive the screws by'- whichthe clips are seourecliin piece, the clips extending 'from the shelvesto the clamping ring to hold the reeeiverin piace.' s

n testimony whereof I have signed my: nome to this specification. j

VERON DURBN.

